During the course of labor and delivery or other medical procedures, it is often necessary to obtain a micro blood sample at the site where the patient is located and then transport the blood sample to the laboratory for analysis. In certain situations, such as fetal blood testing, only a small amount of blood may be available for testing. The blood sample is generally drawn into a small diameter glass capillary tube. The internal surface of the capillary tube is coated with heparin or another suitable chemical anticoagulant to maintain the blood in a liquid form for testing. To promote mixing of the blood with the chemical anticoagulant, a small metal cylinder known as a "flea" is placed inside the capillary tube. The flea is made of ferrous metal which causes the flea to be attracted to a magnet. The diameter of the flea is smaller than the inside diameter of the capillary tube, thus allowing the flea to move freely inside the capillary tube through the blood sample therein. A ring magnet with the capillary tube extending therethrough is moved up and down the length of the capillary tube, causing the flea inside the capillary tube to also move up an down the capillary tube, thereby stirring the blood sample and mixing it with the chemical anticoagulant.
When a blood sample is withdrawn, the ends of the capillary tube are sealed for transportation using conventional test tube sealing putty or rubber boot caps. A lab technician or other medical personnel must then quickly hand carry the capillary tube with the blood sample from the blood withdrawal site to the laboratory so that the blood sample may be analyzed and a report returned to the attending physician. This is especially important in child labor and delivery, where the results of the blood test may dictate whether a Caesarian section must be performed. Under a time-critical circumstance such as this, the blood sample must be quickly transported to the laboratory, while keeping the fragile capillary tube intact and using the ring magnet and the flea to prevent coagulation of the blood sample. If the capillary tube should break or the blood coagulate, the sample may not be suitable to assure test results. In a labor and delivery situation, there may not be time to extract another blood sample for testing. Typically, the capillary tube containing the blood sample is transported by a technician holding the fragile capillary tube in one hand while grasping and reciprocally moving the ring magnet along the length of the capillary tube using the other hand. These twin tasks must often be accomplished while quickly walking through a crowded hospital hallway or taking a crowded elevator between the blood withdrawal site and the laboratory.
The fragility of the capillary tube and the need to constantly slide the magnet up and down the tube makes it difficult to quickly transport the capillary tube without breaking it. Therefore, it can be appreciated that there is a significant need for an apparatus to safely transport blood samples while allowing a magnet to slide freely about the capillary tube without breaking it. The present invention fulfills these needs, and further provides other related advantages.